The present invention relates to a shutter device that selectively opens and closes a discharge outlet through which powder passes, a toner storage unit that stores toner discharged from a discharge outlet opened/closed by the shutter device, and an image forming apparatus including this toner storage unit.
Some electrophotography image forming apparatuses are configured to supply toner to a developer tank from a toner container that is detachably attached to the apparatus. Electrophotography image forming apparatuses collects toner remaining on a photoreceptor after a transfer step to a toner tank.
Toner storage units including a developer tank and a toner tank store toner conveyed by a toner conveyance section. The toner conveyance section is configured to discharge toner conveyed by the rotation of the conveyance screw through a discharge outlet formed at one end portion of the cylindrical body to the developer tank or the toner tank. The discharge outlet is selectively opened/closed by a shutter device.
The shutter device includes a shutter member that is an annular body rotatably fitted around the outside of one end portion of the cylindrical body of the toner conveyance section, the shutter member including an opening with substantially the same shape of the discharge outlet as described in JP 2009-168856 A, for example. The rotation of the shutter member to let the opening thereof opposed to the discharge outlet allows toner to be discharged through the discharge outlet into the developer tank.
Between the inner circumferential face of the shutter member and the cylindrical body of the toner conveyance section and between the outer circumferential face of the shutter member and the recess of the developer tank or the toner tank are provided seal members to prevent the leakage of toner.
Disposing the individual seal members between the inner circumferential face of the shutter member and the cylindrical body of the toner conveyance section and between the outer circumferential face of the shutter member and the recess of the developer tank or the toner tank, however, makes an assembly process complicated because of an increase in the number of components. That is, such a configuration requires an operation to attach the seal members individually at the inner circumferential face of the shutter member or the circumferential face of the cylindrical body of the toner conveyance section and at the outer circumferential face of the shutter member or the inner circumferential face of the recess. Such a problem occurs not only in toner storage units but also generally in devices letting powder discharged through a discharge outlet opened/closed by a shutter member.
It is an object of the present invention to provide a shutter device, a toner storage unit and an image forming apparatus facilitating the attachment of a seal member to an inner circumferential face and an outer circumferential face of a shutter member, thus enabling a simple assembly process.